QUESTION PAPER 1

Chapter 5: Work, Energy and Power

Original chapter-specific practice paper

Maximum Marks: 40Suggested time: 60 minutes

Instructions: Answer all 20 questions. Marks are shown in brackets. Show calculation steps and units. Original practice questions, not an official examination paper.

Section A · 1-mark questions — 8 × 1 = 8 marks

When is work zero with displacement?[1]
Kinetic energy?[1]
SI unit of power?[1]
Work-energy theorem?[1]
Spring energy?[1]
What is conserved in an isolated elastic collision?[1]
Near-earth gravitational potential energy?[1]
Work by centripetal force in uniform circular motion?[1]

Section B · 2-mark questions — 6 × 2 = 12 marks

10 N over 4 m along force: work?[2]
3 kg at 4 m/s: K?[2]
100 W for 20 s: energy?[2]
200 N perpendicular to 5 m displacement: work?[2]
k=200 N/m, spring stretched .1 m: energy?[2]
1 kg cart at 5 m/s sticks to stationary 4 kg: speed?[2]

Section C · 3-mark questions — 4 × 3 = 12 marks

2 kg speeds from 2 to 6 m/s: net work?[3]
5 kg falls 3 m, g=10: final speed?[3]
F=4x N from x=0 to 3 m: work?[3]
1000 kg car at 20 m/s stops in 50 m: W and force magnitude?[3]

Section D · 4-mark questions — 2 × 4 = 8 marks

2 kg drops 5 m frictionlessly, g=10: speed; with 20 J loss?[4]
1 kg cart at 8 m/s sticks to 3 kg stationary: speed and energy loss?[4]

End of paper — review signs, units and working.

Open marking scheme and model answers

Attempt the paper before opening the key. Multi-mark answers show expected principles and results; award partial credit for valid intermediate steps.

Q1 · 1 mark
When force is perpendicular to displacement.
Suggested allocation by section: 1-mark questions earn one mark for the correct fact, formula or unit; 2-mark questions normally award one mark for the principle/formula and one for the explanation or result; 3-mark questions award credit for the relation, working/reasoning and result with unit; 4-mark questions award credit for the principle, equation, working and final answer/interpretation. Accept equivalent correct methods.

Q2 · 1 mark
½mv².
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q3 · 1 mark
Watt.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q4 · 1 mark
Net work equals change in kinetic energy.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q5 · 1 mark
½kx².
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q6 · 1 mark
Momentum and kinetic energy.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q7 · 1 mark
mgh.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q8 · 1 mark
Zero.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q9 · 2 marks
40 J.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q10 · 2 marks
24 J.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q11 · 2 marks
2000 J.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q12 · 2 marks
0 J.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q13 · 2 marks
1 J.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q14 · 2 marks
1 m/s.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q15 · 3 marks
32 J.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q16 · 3 marks
√60≈7.75 m/s.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q17 · 3 marks
18 J.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q18 · 3 marks
−200 kJ; 4000 N.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q19 · 4 marks
10 m/s; √80≈8.94 m/s.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.

Q20 · 4 marks
2 m/s; 24 J lost.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.